Fungicidal compound of the formula c8n4s3



Sept- 19, 1961 A. VAN ScHooR ETA!` 3,000,780

FUNGICIDAL COMPOUND 0F' THE FORMULA 8 4 3 Filed April 28, 1959 Y y ATTORNEYS United States Patent O 3,000,780 FUNGICIDAL COMPOUND F THE FORMULA CNisa Albert van Schoor, Trasa, near Darmstadt, and Ernst Jacobi, Siegmund Lust, Horst Flemming, and Otto Wilhelm Mller, Darmstadt, Germany, assignors to E. Merck Aktiengesellschaft, Darmstadt, Germany Filed Apr. 28, 1959, Ser. No. 809,481 2 Claims. (Cl. 167-33) or other alkali Imetal salts thereof with an oxidizing agent.

The compound of the composition C8N4S3 is produced by both methods in the form of yellow crystals having a melting point of about ISI-183 C. r[The compound is insoluble in water and petroleum ether but is soluble in acetone, methylene chloride, chloroform, ethyl acetate, benzene and hot alcohol. Evidently an oxidation product of 1,2-dimercapto-1,Z-dicyan-ethene is concerned. The empirical formula and infrared absorption spectrum do not exclude that the compound may be of the formula:

The ultra violet spectrum of the compound according to the invention has four distinct maxima at the wave lengths indicated in the following together with the associated molar extinctions:

347 mp.: e=5,460 284.5 mit: e=7,410 236.5 my.: e=11,300 216 my.: e=11,700

Biological tests have shown that the compound according to the invention possesses excellent fungicidal and fungistatic activity with a very broad effective spectrum. The compound, for example, was found effective against fungi of such widely varying types as Rhizoctonia solani, Venturin inaequalis and Alternaria sp. It is also, for example, excellently suited for seed disinfection. Furthermore, it is extremely well tolerated by plants. No phytotoxic damage -was observed on bush beans, toma-to plants, 1 yr. sylvaner grape vines and geranium plants 7.'fhen a 1% spray of such compound was applied to such plants growing in a greenhouse. Furthermore, the fungicidal activity of the compound is vastly superior to that of other recognized fungicides. In comparative tests with tetramethyl-thiuramdisulde and N-trichloro-thiotetrahydro-phthalimide on various test fungi it was found that the fungicidal activity of the compound according to the invention was ten times greater and that its fungicidal activity was seven times greater than that of zinc methyl dithiocarbamatc.

The novel fungicidal compound according to the invention can be incorporated in the usual forms of compositions employed in the control of fungi, such as, for example, sprays, dusts which are prepared by the addition of the usual adjuvant fillers and/or diluents. Also, solutions or emulsions of the compound, which can be dispersed by the aerosol process, can be prepared with the aid of the usual solvents. All forms of application in general contain from about 1% to at most about of the active novel compound.

'Iihe accompanying drawing shows the infrared absorption spectrum of the novel sulfur containing cyanide of tte composition CBN4S, according to the invention in Br. f

The following examples will serve to illustrate several modes of preparation of the novel compound according to the invention and fungicidal compositions containing the same.

Example 1 10 g. of the disodium salt of 1,2dimercapto1,2dicyan ethene were suspended in cc. of acetone and the suspension cooled to 20 C. 15 grams of bromine vapor were introduced therein over a period of 2 hours and the mixture stirred further until all of the bromine had reacted. The acetone was then distilled ot and water was added to the residue to effect crystallization thereof. ll-220 C. It was purified by recrystallization from benzene to produce a yellow crystalline product having a melting point of 181-183 C. Methylene chloride or alcohol can also be used for such recrystallization.

Example 2 l2 g. of 3% H2O2 were diluted with 100 cc. of 2 n HCI, and a solution of 1.8 g. of the disodium salt of 1,2-dimercapto-l,2dicyan ethene in 25 cc. of water was slowly dropped in over a 45 minute period while maintaining a temperature of 05 C. The mixture was stirred for a further l5 minutes at the same temperature. The crystals which separated out melt at C. Yellow crystals having a melting point of 180 C. were obtained therefrom by recrystallization from ethyl acetate. The compound was identical with that obtained in Example 1.

Example 3 A mixture of the disodium salt of 1,2-dimercapto- 1,2-dicyan-ethene and toluene sulfonic acid chloride in a molar ratio of 1.2:2 was heated to boiling in acetone for 10 hours. The reaction product was purified by chromatographing over silica gel. Crystals were obtained from the middle fraction which after repeated recrystallization from ethyl acetate melted at 181 C.

Example 4 9.8 g. of 1,2-dibromo-2-phenyl-ethyl methyl ketone were dissolved in 50 cc. of acetone and 8.2 g. of the disodium salt of the l,2-dimercapto-l,2-dicyan-ethene added thereto at 20 C. while cooling the reaction mixture. The reaction mixture was then permitted to stand for 16 hours at 20 C. and then boiled lfor V2 an hour. The NaBr produced was filtered oil on a suction lter and iltrate freed of solvent. The residue was taken up in methylene chloride, washed with water, dried with CaCl, and treated with active carbon. The product was then fractionated chromatographically in a benzene solution over silica gel. The middle fractions gave crystals of a melting point of 173-176 C. which after recrystallization from benezene melted at 181-183 C. These The crude product had a melting point of- .ground together to form a line powder.

crystals according to mixed melting point, analysis and color were identical with the material obtainedy in the preceding examples.

Example 5 80 g. of carbon disulfide were dissolved in 375 g. of dimethylformamide and slowly reacted with 50 g. of sodium cyanide. Thereafter 270 g. of iron III chloride (FeCl3-6H2O) were slowly added. After the exothermic reaction was completed, water was added and after longer standing the crystalline substance was lltered off on a suction lfilter. After separating otf the sulfur with the aid of carbon disuliide and recrystallization from ethyl acetate it had a composition of C,N4S3 and melted at 18l-l83 C. The U.V. absorption maxima thereof were at 347, 284.5, 236.5 and 216 ma.

The sulfur can also be removed from the crude product by extraction of the CN4S, compound with acetone. Also, instead of splitting E the sulfur with water, it can be split olf by addition of chloroform. In this instance the CaNSa compound produced does not crystallize out, but can be recovered from the chloroform solution.

Example 6 80 g. of carbon disulfide were dissolved in 375 g. of dimethylformamide and slowly reacted with 50 g. of sodium cyanide. Thereafter 40 g. of manganese dioxide (80-90%), 90 g. of glacial acetic acid and 50 g. of acetic acid anhydride were slowly added while stirring. After the exothermic action had completed 750 g. of water were added and the mixture allowed to stand overnight.

The crystalline substance was filtered ol and after removal of sulfur as in Example and recrystallization from ethyl acetate it had a composition of CsN4S3 and melted at ISI-183 C. The U.V. absorption maxima thereof were at 347, 285.5, 236.5 and 216 ma.

Example 7 80 parts by weight of the sulfur containing cyanide C8N4S3, 10 parts by weight of kaolin, 8 parts by weight of powdered dried sulfite waste liquor and 2 parts by weight of isobutyl naphthalene sodium sulfonate were This powder upon admixture with water to form a dilute suspension (about 1% of active substance) was suited for spraying plants to be protected from attack by fungi.

Example 8 A mixture of 30 parts by weight of the sulfur containing cyanide CaN4S3, l0 lparts by weight of colophony and parts by weight of kaolin was finely ground. The

powder was excellently suited as a seed grain disinfecting powder and adhered well to the seed treated therewith.

Example 9 Example I 0 25 parts by weight of the crude about 60% of C3N4S3 and 40% of S were mixed with 60 parts by weight of flowers of sulfur and l5 parts by weight of 1,5cndomethylene-3,7dinitroso1,3,5,7tetraazo-cyclooctane. When this powder was heated Harnelessly to about 200 C. it produced an aerosol which deposits as a line coating on surfaces subjected to such aerosol.

We claim:

1. A method of controlling the growth of fungi on materials subject to fungal growth which comprises applying thereto an effective amount of a sulfur containing cyanide of the formula CBN4S3 having a melting point of about 181-183" C., said compound being insoluble in water and petroleum ether but soluble in acetone, methylene chloride, chloroform, ethyl acetate, benzene and hot alcohol and the ultra violet spectrum of said compound having four distinct absorption maxima at the following wave lengths 347 ma, 284.5 ma, 236.5 ma and 216 my. and the infra red absorptionspectrum of said compound being substantially in accordance with the spectrum given in the accompanying drawing.

2. A sulfur containing cyanide of the formula C8N4S3 having a melting point of about 181-1 83 C., said compound bcing insoluble in water and petroleum ether but soluble in acetone, methylene chloride, chloroform, ethyl acetate, benzene and hot alcohol and the ultra violet spectrum of said compound having four distinct absorption maxima at the following wave lengths 347 ma' 284.5 ma, 236.5 ma, and 216 ma and the infra red absorption spectrum of said compound being substantially in accordance with the spectrum given in the accompanying drawing. A

product consisting of No references cited. 

1. A METHOD OF CONTROLLING THE GROWTH OF FUNGI ON MATERIALS SUBJECT TO FUNGAL GROWTH WHICH COMPRISES APPLYING THERETO AN EFFECTIVE AMOUNT OF A SULFUR CONTAINING CYANIDE OF THE FORMULA C8N4S3 HAVING A MELTING POINT OF ABOUT 181-183*C., SAID COMPOUND BEING INSOLUBLE IN WATER AND PETROLEUM ETHER BUT SOLUBLE IN ACETONE, METHYLENE CHLORIDE, CHLOROFORM, ETHYL ACETATE, BENZENE AND HOT ALCOHOL AND THE ULTRA VIOLET SPECTRUM OF SAID COMPOUND HAVING FOUR DISTINCT ABSORPTION MAXIMA AT THE FOLLOWING WAVE LENGTHS 347 MU, 284.5 MU, 236.5 MU AND 216 MU AND THE INFRA RED ABSORPTION SPECTRUM OF SAID COMPOUND BEING SUBSTANTIALLY IN ACCORDANCE WITH THE SPECTRUM GIVEN IN THE ACCOMPANY DRAWING.
 2. A SULFUR CONTAING CYANIDE OF THE FORMULA C8N4S3 HAVING A MELTING POINT OF ABOUT 181-183*C., SAID COMPOUND BEING INSOLUBLE IN WATER AND PETROLEUM ETHER BUT SOLUBLE IN ACETONE, METHYLENE CHLORIDE, CHLOROFORM, ETHYL ACETATE, BENZENE AND HOT ALCOHOL AND THE ULTRA VIOLET SPECTRUM OF SAID COMPOUND HAVING FOUR DISTINCT ABSORPTION MAMIMA AT THE FOLLOWING WAVE LENGTHS 347 MU, 284.5 MU, 236.5 MU, AND 216 MU AND THE INFRA RED ABSORPTION SPECTRUM OF SAID COMPOUND BEING SUBSTANTIALLY IN ACCORDANCE WITH THE SPECTRUM GIVEN IN THE ACCOMPANYING DRAWING. 